From the first link in the OP you're replying to:
> The United States Senate Committee on Finance launched an 18-month investigation of Gilead's Sovaldi pricing, and argued in its 2015 report that Gilead set prices high in disregard of the human cost and in order to set the stage for a higher eventual price for Sovaldi's successor, Harvoni. The committee's investigation, based in part on internal documents obtained from Gilead, revealed that the company had considered prices ranging from $50,000 to $115,000 per year, trying to strike a balance between revenue and predicted activist and public relations blowback, with little regard to research and development costs.
The pricing was found to be intentionally divorced from R&D costs. They are charging as much as they can because they can, not because of R&D.